Treponema medium glycoconjugate inhibits activation of human gingival fibroblasts stimulated with phenol-water extracts of periodontopathic bacteria.

Oral treponemes are well-known as causative agents of periodontal diseases; however, the details have not been fully clarified. Here, we examined the effects of Treponema medium glycoconjugate on the activation of human gingival fibroblasts using phenol-water extracts from Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum subsp. nucleatum, and Actinobacillus actinomycetemcomitans. The phenol-water extracts activated human gingival fibroblasts to mediate IL-8 production, as well as IL-8 mRNA expression, phosphorylation of p38 mitogen-activated protein kinase, and expression of intercellular adhesion molecule-1. T. medium glycoconjugate exhibited no activation of human gingival fibroblasts, while phenol-water extract-induced activation of human gingival fibroblasts was clearly inhibited by T. medium glycoconjugate. Furthermore, binding of biotinylated phenol-water extracts to CD14 in the presence of LPS-binding protein was blocked with T. medium glycoconjugate. These results suggest that T. medium glycoconjugate has an inhibitory effect on host cell activation by periodontopathic bacteria caused by binding to CD14- and LPS-binding protein.

The interaction of ubiquinone-3 with phospholipid membranes.

The effects of ubiquinone-3 (UQ) on dipalmitoylphosphatidylcholine (DPPC) membrane were studied by surface monolayer, differential scanning calorimetry (DSC) and fluorescence techniques. DPPC and UQ are proved to be freely miscible in the mixed monolayer at an air/water interface, and to be partially miscible in bulk phase, i.e. bilayer and solid phase. There is a condensing interaction between UQ and DPPC in the UQ/DPPC mixed monolayers. The solubility of UQ in the DPPC is about 20 mole% and the solubility of DPPC in UQ is about 10 mole%. The membrane fluidity of DPPC was increased by the addition of UQ and the phase transition temperature was decreased.

The effect of the lipid A analog E5531 on phospholipid membrane properties.

In order to determine the effect of the lipid A analog, E5531, on phospholipid membranes, we used dipalmitoylphosphatidylcholine (DPPC) and investigated the physicochemical interaction between E5531 and DPPC membranes. E5531 and DPPC are miscible in the bulk phase at 25 degrees C. Within the E5531 mole fraction range (X(E5531)) of 0-0.5, E5531 decreased the zeta potentials of DPPC membranes but did not change the size of the DPPC liposomes. E5531/DPPC mixtures formed liposome-like structures. E5531 increased the fluidity of the DPPC membrane and decreased pyrene diffusion in the membrane. E5531 decreased the phase transition temperature and the cooperative interactions between DPPC molecules. These effects of E5531 on phospholipid membranes were different from those of lipid A from Escherichia coli and Salmonella minnesota.

A dual computed tomography linear accelerator unit for stereotactic radiation therapy: a new approach without cranially fixated stereotactic frames.

PURPOSE: To perform stereotactic radiation therapy (SRT) without cranially fixated stereotactic frames, we developed a dual computed tomography (CT) linear accelerator (linac) treatment unit. METHODS AND MATERIALS: This unit is composed of a linac, CT, and motorized table. The linac and CT are set up at opposite ends of the table, which is suitable for both machines. The gantry axis of the linac is coaxial with that of the CT scanner. Thus, the center of the target detected with the CT can be matched easily with the gantry axis of the linac by rotating the table. Positioning is confirmed with the CT for each treatment session. Positioning and treatment errors with this unit were examined by phantom studies. Between August and December 1994, 8 patients with 11 lesions of primary or metastatic brain tumors received SRT with this unit. All lesions were treated with 24 Gy in three fractions to 30 Gy in 10 fractions to the 80% isodose line, with or without conventional external beam radiation therapy. RESULTS: Phantom studies revealed that treatment errors with this unit were within 1 mm after careful positioning. The position was easily maintained using two tiny metallic balls as vertical and horizontal marks. Motion of patients was negligible using a conventional heat-flexible head mold and dental impression. The overall time for a multiple noncoplanar arcs treatment for a single isocenter was less than 1 h on the initial treatment day and usually less than 20 min on subsequent days. Treatment was outpatient-based and well tolerated with no acute toxicities. Satisfactory responses have been documented. CONCLUSION: Using this treatment unit, multiple fractionated SRT is performed easily and precisely without cranially fixated stereotactic frames.

Prevention of endotoxin-induced lethality in mice by calmodulin kinase activator.

Porphyromonas gingivalis strain 381 lipid A showed lower activity in inducing interleukin (IL)-1alpha and IL-1beta production and cytokine mRNA expression than synthetic Escherichia coli lipid A (compound 506) in alveolar macrophages of C57BL/6 mice. Both the lipid As induced tumor necrosis factor alpha in alveolar macrophages and IL-6 in peritoneal macrophages. A calmodulin (CaM) antagonist, W-7, inhibited IL-1beta production and its mRNA expression induced by P. gingivalis lipid A but not compound 506 in alveolar macrophages. A CaM kinase activator reduced the induction of IL-1beta in the serum of mice when administered with compound 506, and protected the mice against the lethal toxicity. The modulation of a variety of intracellular enzymes including the CaM kinase may result in clinical control of endotoxic sepsis.

Immunobiological activities of a chemically synthesized lipid A of Porphyromonas gingivalis.

A synthetic lipid A of Porphyromonas gingivalis strain 381 (compound PG-381), which is similar to its natural lipid A, demonstrated no or very low endotoxic activities as compared to Escherichia coli-type synthetic lipid A (compound 506). On the other hand, compound PG-381 had stronger hemagglutinating activities on rabbit erythrocytes than compound 506. Compound PG-381 also induced mitogenic responses in spleen cells from lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice, as well as LPS-responsive C3H/HeN mice. The addition of polymyxin B resulted in the inhibition of mitogenic activities, however, compound 506 did not show these capacities. Additionally, compound PG-381 showed a lower level of activity in inducing cytokine production in peritoneal macrophages and gingival fibroblasts from C3H/HeN mice, but not C3H/HeJ mice, in comparison to compound 506. Thus, this study demonstrates that the chemical synthesis of lipid A, mimicking the natural lipid A portion of LPS from P. gingivalis, confirms its low endotoxic potency and immunobiological activity.

Detectable dioxins in human saliva and their effects on gingival epithelial cells.

Dioxin, a powerful hormone-disrupting chemical, exhibits serious health effects when it reaches body fat. Here we analyzed coplanar polychlorinated biphenyls (PCBs) and polychlorinated-dibenzo-p-dioxins (PCDDs) in human saliva as compared with blood specimens, and examined their effects on human gingival epithelial cells (HGEC). High levels of tri- and tetrachlorinated PCBs were found in saliva, whereas we detected predominantly hexa- and heptachlorinated PCBs in blood. Among PCDDs, the saliva and blood specimens contained mainly 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (OCDD). Among the toxic dioxins proposed by the World Health Organization (WHO) in 1998, 2,3',4,4',5-pentachlorobiphenyl (PCB 118) and OCDD, which were mainly found in saliva, significantly induced IL-8 production in HGEC. Furthermore, these two dioxins markedly augmented IL-8 production stimulated with fimbriae from Porphyromonas gingivalis, which is well-known as a pathogenic factor in periodontal diseases. These results suggest that dioxins in saliva may be a risk factor for periodontal diseases.

Interaction of retinol with dipalmitoylphosphatidylcholine and their formation of small dispersed particles.

Stable aqueous dispersions of all-trans-retinol (vitamin A, VA) were obtained by sonication with dipalmitoylphos-phatidylcholine (DPPC) in the VA mole fraction range 0.1-0.7. In order to clarify the dispersal mechanism, the dispersed particles were characterized and the interaction between VA and DPPC was investigated using several physicochemical techniques. Dynamic light scattering measurements showed that the diameter of the dispersed particles was 50-70 nm. A limited amount of VA was incorporated into DPPC bilayer membranes (approximately 5 mol%). The trapped aqueous volume inside the particles was determined fluorometrically using the aqueous space marker calcein and the volume in the VA/DPPC particles was decreased markedly with the addition of VA into small unilamellar vesicles of DPPC. The decline in the fraction of vesicular particles was also confirmed by fluorescence quenching of N-dansylhexadecylamine in the DPPC membrane by the addition of the quencher CuSO4. These results indicate that the excess VA separated from the DPPC bilayers is stabilized as emulsion particles by the DPPC surface monolayer.

Various designs of ceramometal crown for implant restorations.

The posterior design of the implant superstructure (the ceramometal crown) was classified into four categories: a ceramometal crown with an access hole on top; a cemented ceramometal crown; a ceramometal crown retained with a lingual screw; and a telescopic ceramometal crown. Cemented ceramometal crowns and telescopic ceramometal crowns are considered simpler, more esthetic, and more resistant to fracture among the four models.

[Closure of median sternotomy incision with EPTFE sutures].

EPTFE (CV-0) suture was utilized for closure of median sternotomy incision in 100 patients under 6 years of age who underwent open heart surgery. During 3 years follow up, except for one dislocation of sternum, all patients have healed without complication. EPTFE suture is swanged to a needle that has the same diameter as the thread, which reduces bleeding from the needle hole. It is radiologically lucent, and therefore does not disrupt chest X-ray, angiography or MRI investigations, in contrast to sternal wires. In addition, in the case of life threatening postoperative complication, EPTFE suture allows rapid and simple access to the heart, without the need to cut wires. We concluded that EPTFE suture can be utilized for closure of median sternotomy in patients under the age of six, without an increased risk of postoperative or long-term complications.

[A case of anaphylaxic shock due to latex glove used on internal examination and on the probe of intrauterine echogram].

A 15 year old female with uterus bicornis bicollis was admitted for operation. She had a history of atopic dermatitis and allergy to buckwheat, raw egg and latex. Two months previously she had developed whole body flushing during dental treatment, and latex glove used by the dentist had been suspected as the cause. Prior to the operation she underwent internal examination and intrauterine echogram in which a latex glove was carelessly used by another gynecologist who had not confirmed her past history. After 30 minutes, dyspnea and urticaria without itching, appeared suddenly. Blood pressure decreased to 80/50 mmHg and heart rate increased to 120 beats.min-1. She was then transferred to our ICU. Methylprednisolone was administered intravenously for dyspnea and circulatory collapse. After 3 hours, the patient made an uneventful recovery. The increased plasma latex protein-specific IgE levels confirmed anaphylaxis to latex. The increasing incidence of potentially life-threatening allergic reactions to latex has caused mounting concern over recent years. We may suspect latex allergy when an anaphylaxic reaction or shock of unknown origin occurs. In hospitals, latex free products must be prepared for use with latex allergic patients and for protection of medical staff with this allergy.

Clinico-pathological studies on the tissue reactions of human pulp treated with various kinds of calcium phosphate ceramics.

The aim of this study was to evaluate the clinical values of calcium phosphate ceramics from the biological point of view. Two kinds of calcium phosphate ceramics, tricalcium phosphate (TCP) and hydroxyapatite (HAP) ceramics with a low sintering temperature (LT) and a high sintering temperature (HT), were applied to exposed pulp wounds in ninety healthy human teeth. Each group was further subdivided into 2 groups with selected granule diameters of 5 microns (S) and 40 microns (L), and investigated clinico-pathologically. Clinically, cases showing some kinds of discomfort symptoms comprised 3/15 of the TCP (S) group, 3/15 of the TCP(L) group, 3/15 of the LT(S) group, 4/15 of the LT(L) group, 2/15 of the HT(S) group, and 3/15 of the HT(L) group. The symptoms were generally slight or very slight and disappeared within eight days in the LT(S) group. Histo-pathologically, inflammatory reactions were observed within 2 weeks. Traumatic injury caused by surgical wound or by mechanical irritation from the materials produced various pathological changes. After the treatment, pulp manifested reparative changes such as cicatrization, formation of new denticles, and dentin apposition on pulp-chamber walls. In many cases, TCP and HAP produced similar effects on human dental pulp. In the TCP(S), the LT(S), and HT(S) groups, a calcified matrix had appended by 3 weeks. In TCP(L), LT(L), and HT(L) groups, the matrix had appended from 3 to 6 weeks. Calcified matrix formation in the LT group was slightly less than in that in the HT of HAP group. In a few cases, complete dentin bridges formed over the exposed pulp surfaces. These results suggest that HAP (both LT and HT) and TCP ceramics are biocompatible and do not harm human dental pulp. These ceramics were found to be clinicopathologically effective in biologically protecting exposed human dental pulp and useful as basic materials in endodontic therapy.

Ultrastructure of initial calcification on exposed human pulp applied with autogenous dentin fragments.

Initial calcification in human dental pulp has been studied with electron microscopy in 20 human teeth over a period of 21 days following pulp exposure and capping with autogenous dentin fragments. Five days after operation, dentin fragments were surrounded by degeneration cells and inflammatory cells. Occasionally a macrophage that had phagocytosed a dentin fragments was observed. Fourteen days after operation, osmiophilic needle-like crystalline structures were found in spherical bodies in the collagen fibrils or on the dentin surface. Ca and P were detected in these needle-like crystalline structures by energy dispersive X-ray analysis. They tended to increase in size and to fuse together to form mineralizing globules with the passage of time. Initial calcification around the dentin fragments developed various patterns, including spherical bodies in the collagen fibrils and direct apposition of needle-like crystals on the dentin fragments.

Case reports on a porous alumina ceramics implant: observations at 14 years after treatment.

Bioceram Porous Implants using alumina are manufactured by Kyocera Corp. We started to use this implant in September of 1984. The subjects were 18 men and 42 women 20 to 70 years of age. We have followed up 65 implants in 60 patients for up to 13 years and 6 months. One implant in 1 patient had to be removed because of post-operative infection and 4 implants in 4 patients had to be removed due to fracturing or detachment. The clinical progress has been good in all the other 60 implants in 55 patients.